1. Technical Field
Compact combination suction devices and liquid separators are disclosed. More particularly, vertical rotary vane pumps are combined with a liquid/air separator using a single motor for providing both suction and liquid/air separation in a compact design. The disclosed combination vertical rotary vane pumps and liquid separators are ideal for use in dental offices, which typically have limited amounts of space available for such equipment.
2. Description of the Related Art
Suction tools and devices are commonly used in operating rooms, dental offices, and the like, to quickly clear excess liquids during medical procedures. For instance, a typical dental office may require a suction device to remove liquids and/or debris from the mouth of a patient while examining the patient's teeth or undergoing a particular procedure in the patient's mouth. Upstream of the suction device is a separator which is used to separate the liquid and solids removed from the patient's mouth before the air flow enters the suction device. Various centrifugal and tank base separators are known.
A typical suction device comprises a pump which compresses air and creates a vacuum or suction. A vacuum may be formed using commonly known pump and/or blower systems, such as liquid ring pumps, rotary vane pumps, blower-based systems, claw systems, and the like. Although these pumps provide adequate suction and performance, they still have their setbacks.
A liquid ring pump comprises a vaned impeller which rotates within a cylindrical housing while a liquid, such as water, is continuously fed into the cylindrical pump casing. As the impeller rotates, centrifugal forces cause the liquid to form a rotating cylindrical ring against the inner wall of the cylindrical housing. This liquid ring forms a series of sealed chambers with the impeller vanes to compress air. Liquid ring pumps are one of the more commonly used vacuum pumps installed in dental offices. This is because liquid ring pumps are reliable and compact in size. However, liquid ring pumps need a constant supply of water to create the sealed compression chambers. This demand for a constant supply of water results in significant water utility fees to the end user, inability to comply with local water conservation measures and other environmental concerns.
One alternative to using water consuming liquid ring pumps is to use rotary vane pumps. Rotary vane pumps employ a vaned rotor that is disposed within a cylindrical housing. The rotor and the cylindrical housing are axially misaligned or offset such that the rotor is never centered within the housing. The vanes are configured to be radially slidable with respect to the rotor and centrifugal forces bias the vanes radially outwardly to maintain contact with the inner wall of the housing. The vanes and the inner wall of the cylindrical housing form at least two sealed chambers. Compression is formed when the respective volumes of the sealed chambers increase and/or decrease as the off-centered rotor rotates. Although rotary vane pumps perform well without requiring a constant supply of water, they are larger than liquid ring pumps. Rotary vane pumps also need oil for lubrication, which raises additional environmental concerns.
Regenerative blowers can also be used to create a vacuum or suction for use with dental applications. Regenerative blowers include a multi-bladed impeller which rotates continuously. A small amount of air slips past one blade and returns to the base of a succeeding blade for reacceleration or “regeneration.” Regenerative blowers do not require water or lubrication. However, regenerative blowers are large and use significantly more electricity than liquid ring pumps.
Claw systems employ rotating claw-shaped lobes which mesh with one another and form sealed chambers when fitted within the vacuum housing. Rotating the claw-shaped lobes varies the volumes of the respective chambers within the housing to create compression or suction. Claw systems do not require water or oil lubrication to maintain properly sealed compression chambers. However, claw systems are large and expensive.
Therefore, there is a need for an improved suction system that provides comparable or better performance while overcoming all of the deficiencies associated with the prior art. Because modern dental offices are operating on thin margins, capital costs and operating costs are primary concerns. Further, as dental offices attempt to operate more efficiently, dental offices are becoming smaller, thereby creating a demand for smaller suction and separator systems. As a result, there is a need for a cost efficient and compact suction device combined with a separator which creates at least as much compression or vacuum as liquid ring pumps without requiring water or oil lubrication and which conserves space.
While the following discussion will be directed toward suction and separation devices for use with dental applications, it will be noted that this application and the devices disclosed herein are applicable to various fields beyond that of suction and separation devices for use with dental applications, and more generally, can be applied to any application requiring solid and/or liquid suction.